# ---
# title: 819. Most Common Word
# id: problem819
# author: Tian Jun
# date: 2020-10-31
# difficulty: Easy
# categories: String
# link: <https://leetcode.com/problems/most-common-word/description/>
# hidden: true
# ---
# 
# Given a paragraph and a list of banned words, return the most frequent word
# that is not in the list of banned words.  It is guaranteed there is at least
# one word that isn't banned, and that the answer is unique.
# 
# Words in the list of banned words are given in lowercase, and free of
# punctuation.  Words in the paragraph are not case sensitive.  The answer is in
# lowercase.
# 
# 
# 
# **Example:**
# 
#     
#     
#     Input: 
#     paragraph = "Bob hit a ball, the hit BALL flew far after it was hit."
#     banned = ["hit"]
#     Output: "ball"
#     Explanation: 
#     "hit" occurs 3 times, but it is a banned word.
#     "ball" occurs twice (and no other word does), so it is the most frequent non-banned word in the paragraph. 
#     Note that words in the paragraph are not case sensitive,
#     that punctuation is ignored (even if adjacent to words, such as "ball,"), 
#     and that "hit" isn't the answer even though it occurs more because it is banned.
#     
# 
# 
# 
# **Note:**
# 
#   * `1 <= paragraph.length <= 1000`.
#   * `0 <= banned.length <= 100`.
#   * `1 <= banned[i].length <= 10`.
#   * The answer is unique, and written in lowercase (even if its occurrences in `paragraph` may have uppercase symbols, and even if it is a proper noun.)
#   * `paragraph` only consists of letters, spaces, or the punctuation symbols `!?',;.`
#   * There are no hyphens or hyphenated words.
#   * Words only consist of letters, never apostrophes or other punctuation symbols.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
